The San Diego Humane Society is investigating the death of a horse that took part in last month's rodeo at Petco Park, officials said Monday.
The 16-year-old bucking male horse died shortly after competing in a saddle bronc event on Jan. 11, according to a report from Dr. Tim Eastman, the attending veterinarian at the rodeo.
While the horse showed "no indication of illness or distress during the competition," Eastman wrote, the horse "was found recumbent and trembling" within 15 minutes of returning to a holding pen. An on-site veterinarian was called, but the horse died during a physical examination.
The report — dated Jan. 13 — states the cause of death is unknown. It also notes that no other horses required treatment during the three-day rodeo.
The San Diego Rodeo Alliance said the death was the result of an "unforeseeable medical event."
In a statement, San Diego Humane Society officials said they were still investigating the cause of death, but was nearing the "final stages of our investigation" and was looking into "whether criminal intent or negligence played a role."
The death comes as animal activists continue to spar with rodeo organizers and rodeo proponents, who say the events are part of long-standing cultural traditions, over whether to restrict or outright ban rodeo events. Proposals forwarded last year by City Councilmember Kent Lee to ban the rodeo or place restrictions on such events held within the city were unsuccessful.